|Publication number||US7457488 B2|
|Application number||US 11/173,687|
|Publication date||Nov 25, 2008|
|Filing date||Jun 30, 2005|
|Priority date||Jun 30, 2005|
|Also published as||US20070003181|
|Publication number||11173687, 173687, US 7457488 B2, US 7457488B2, US-B2-7457488, US7457488 B2, US7457488B2|
|Inventors||Rick C. Stevens, Allison Hernandez|
|Original Assignee||Lockheed Martin Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (11), Non-Patent Citations (4), Classifications (23), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present disclosure generally relates to temperature sensing. And, in particular, the present disclosure relates to temperature sensing in optical networks.
In an optical network, light waves are typically transmitted through an optical pathway. At one end of the optical pathway, a transmitter encodes a signal transmitted as light waves. These light waves are transmitted through the optical pathway to a receiver. The receiver receives the light waves and decodes the signal.
In an optical network, an optical pathway is typically constructed from a number of pathway sections. A pathway section is typically formed by fiber optic cable. The ends of adjacent sections are joined together by connectors, to form a single continuous optical pathway.
Optical pathways experience attenuation, which is a reduction in signal strength during the transmission of a signal. As light waves are transmitted through an optical pathway (e.g. optical fiber, splices, and connectors) the waves weaken, resulting in attenuation. This shortens the distance that a receiver can be positioned from a transmitter to receive an accurate signal.
Optical pathways also may experience a sensitivity to temperature. The temperature of an optical pathway's materials can adversely affect the transmission of light through the optical pathway by degrading the signal. For example, a temperature influence, such as heat can come from a number of sources, including the optical network and one or more of its components. Although this influence of temperature may degrade the signal in an optical pathway, it can be difficult to identify the temperature influencing source causing this degradation.
In identifying sources that influence the temperature in an optical pathway, temperature sensors can be placed at locations along the optical pathway. However, this method utilizes the purchase and installation of temperature sensors. This method can also involve extensive wiring to transmit the temperature information from each sensor to the operator of the optical network.
In another method of identifying temperature influencing sources, part or all of the optical network can be removed from the field and taken to a laboratory environment where it can be checked for temperature influencing sources. However, this method may require that the network be taken out of service, resulting in network downtime. Furthermore, this method is unable to detect temperature influencing sources specific to the field environment. The general temperature environment in the laboratory may be different from that of the field. Therefore, such methods may not be able to identify the existence of, or the significance of, a temperature influencing source.
Embodiments of the present disclosure provide components, systems, and networks to sense temperature along an optical pathway of an optical network, while the pathway remains in its field environment.
In various embodiments of the present disclosure, a component contains a temperature sensitive material and can be used to join together optical pathway sections. For example, the component may be provided as a connector, such as a splice material, a connector body, or another type of structure between optical pathway sections.
The temperature sensitive material utilized in such components has light transmission characteristics that change based upon the temperature of the temperature sensitive material. At a first temperature, the temperature sensitive material transmits a number of wavelengths of light. At a second temperature, the temperature sensitive material absorbs one or more particular wavelengths of light that had been transmitted at the first temperature.
In some embodiments of the present disclosure, the temperature sensitive material can absorb one or more light wavelengths, or one or more ranges of light wavelengths, at a particular temperature. The temperature sensitive material can also absorb one or more light wavelengths, or one or more ranges of light wavelengths, at several different temperatures. Accordingly, in various embodiments, these temperature sensitive materials can transmit certain light wavelengths within a range of temperatures.
Such temperature sensitive materials can be manufactured so that a material transmits a number of known light wavelengths at a first known temperature but absorbs one or more of the known light wavelengths at a second known temperature. For example, in some embodiments, a temperature sensitive material can be manufactured to absorb one or more light wavelengths between 1300 and 1400 nanometers, among other ranges.
Accordingly, such temperature sensitive materials can be used as temperature sensors based upon the light transmission characteristics exhibited by the material. For example, by knowing the temperature sensitive material's temperature dependent light transmission characteristics, the temperature at the location of the temperature sensitive material can be ascertained.
Temperature sensitive materials allow one or more known light wavelengths to pass through at a particular temperature, but block the transmission of one or more of those light wavelengths at another temperature. This selective absorption can be observed by comparing the characteristics of a type of light signal having a number of known wavelengths to a light signal of the same type passed through the temperature sensitive material. If the temperature sensitive material allows a known light wavelength to pass through, then an observer can ascertain that the device is not at the absorption temperature. If the temperature sensitive material blocks the transmission of one or more of the known light wavelengths, then an observer can ascertain the temperature of the temperature sensitive material based upon its known characteristics of absorption at various particular temperatures.
In various embodiments of the present disclosure, an optical network or system can be used to sense temperature along one of its optical pathways while the pathway remains in its field environment. The optical pathway can have a number of pathway sections. An optical network can include an optical emitter positioned to emit a light wave through the optical pathway and a receiver positioned to receive the light wave via the optical pathway.
An optical network can further include a temperature sensitive material placed along the optical pathway such that light passes through the material. For example, the material can be a portion of a connector, positioned between a pair of pathway sections forming the optical pathway. As the light passes through the temperature sensitive material, one or more characteristics of a light wave passing through the material can change based upon temperature.
One type of temperature sensitive material is a semiconductor nanocrystal material. One form of semiconductor nanocrystal material is a quantum dot thin film. Quantum dot thin films can be made, for example, from crystals composed of periodic groups of II-VI, III-V, or IV-VI materials (also known as periodic groups 12-16, 13-15 or 14-16 under the current IUPAC system). Examples of quantum dot thin film materials include lead-selenide, lead-sulfide, lead-telluride, cadmium-selenide, and cadmium-sulfide, among others.
Such temperature sensitive materials can be provided in a variety of different manners. For example, the materials can be provided as films, as resins, as powders, or as particles among other forms. These materials can be used independently or in conjunction with other materials. For example, in embodiments utilizing a thin film, a temperature sensitive material resin can be cured (e.g., UV, thermally, and/or chemically) in the form of a thin film or can be coated onto a thin film material. In such embodiments, the temperature sensitive material can be cured, molded, mixed, bonded, or adhered, among other combination processes to one or more other materials which may or may not be temperature sensitive.
In some embodiments of the present disclosure, a transmitter and receiver can be used to send and receive a test pulse via the optical pathway of the optical network. The transmitter and receiver can be those used to send light signals for general communication in the optical network or can be an additional transmitter and/or receiver, provided to send a test pulse, for example a test pulse can be used to detect one or more emission spectra of the test pulse and this information can be used to determine temperature.
Temperature sensitive materials can have additional uses within optical networks. For example, in some embodiments, the temperature sensitive material can act as a thermoelectric cooling component. In some embodiments, the temperature sensitive material can act as a heat sink.
As stated above, the temperature sensitive material can be used to form a portion or all of a connector between optical pathway sections. In some embodiments, the connector can include an outer portion to aid in securing the optical pathway sections together. Such outer portions can be fabricated from plastics, polymers, metals, and other suitable materials.
In various embodiments, the connector can also include an inner portion constructed from a temperature sensitive material. In such embodiments, the inner portion can form an interface between an end of a first optical pathway section and an end of a second optical pathway section.
Further, in some embodiments of the present disclosure, a network or system can include a tunable transmitter that can be tuned based upon changes to the characteristics of the light wave that passes through the temperature sensitive material. This transmitter can be used as the emitter for emitting general communications on the optical network or system, and/or as the emitter for sending test pulses.
In various embodiments of the present disclosure, logic circuitry can be provided that can analyze one or more characteristics of the light wave passing through the connector to determine whether they have changed and/or what adjustments to make to the signal being transmitted. In some embodiments, the logic circuitry can be a processor or state type circuitry, among other logic circuit types. In some embodiments of the present disclosure, a tunable transmitter can be tuned based upon the analysis performed by the logic circuitry.
The present disclosure includes a number of device and system embodiments for sensing temperature along the optical pathways of an optical network. Embodiments of the present disclosure will now be described in relation to the accompanying drawings, which will at least assist in illustrating the various features of the various embodiments.
Although generally termed a transmission component 110, in the embodiment illustrated in
Accordingly, in this embodiment, the transmitter 112 is positioned to transmit light waves into optical pathway section 120-T. The optical pathway section 120-T is positioned to transmit light waves into the splitter 130. The splitter 130 transmits light waves from the transmitter 112 into optical pathway section 121-0.
Optical pathway sections 121-0 and 121-1 are joined together by connector 140-1. The optical pathway sections 121-1 and 121-2 are similarly joined together by connector 140-2. Further, optical pathway sections 121-2 and 121-3 are joined together by connector 140-3. And, optical pathway sections 121-3 and 121-M are joined together by connector 140-L. The light waves pass through the optical pathway sections 121-1 through 121-M and through connectors 140-1 through 140-L.
In the embodiment illustrated in
In some embodiments, logic circuitry 116 can be associated with (e.g., can include or be connected to) transmitter 112 to obtain information from transmitter 112. Logic circuitry 116 can also be associated with the receiver 114 to obtain information from receiver 114.
Transmitter 112 can be used to transmit encoded and/or non-encoded signals in the form of light waves. The transmitter 112 can be associated with logic circuitry to encode information into the signals. Encoding can be accomplished, for example, by modulating frequency, wavelength, and/or intensity of a light signal.
In some embodiments, connectors 140-1, 140-2, 140-3, and 140-L can each include a temperature sensitive material. As stated above, various temperature sensitive materials can have light transmission characteristics that change based upon the temperature of the temperature sensitive material. For example, at one temperature, a temperature sensitive material transmits a particular wavelength of light. At another temperature, the temperature sensitive material absorbs that same particular wavelength of light. In this way, the temperature at the location of the temperature sensitive material can be determined. In some embodiments based upon this temperature information, the light signal can be modified.
Temperature sensitive connectors can be made entirely of temperature sensitive material or can have a portion, such as the portion through which the light signals pass, made from temperature sensitive material. Temperature sensitive connectors can be used in optical networks, such as those illustrated in
Various types of temperature sensitive materials that can be used in the various embodiments of the present disclosure can identify a single wavelength, multiple separate wavelengths, or multiple wavelengths in a range. As such, those of ordinary skill in the art will realize upon reading the present disclosure that the functions that can be accomplished with these temperature sensitive materials can change based upon the material or combination of materials utilized and the logic circuitry employed to interpret the changes in the light waves.
Connectors can be of differing sizes, shapes, styles, or types. For example, the connectors in
In various embodiments of an optical network 100, the connectors can have a variety of temperature dependent light transmission characteristics. For example, a connector can be designed to transmit a single range or multiple ranges of light wavelengths. Similarly, a connector can be designed to absorb a single range or multiple ranges of light wavelengths. Further, each connector can have temperature dependent light transmission characteristics that are similar to or different from one or more of the other connectors.
As stated above, various types of logic circuitry can be used in the various embodiments of the present disclosure. The logic circuitry can be used to identify changes in a light wave transmitted through an optical pathway based upon reference data stored in memory, measured data from the transmitter and/or receiver components, and/or other such temperature or material information that can be used to determine one or more temperatures and/or the effects of temperatures on the optical network. In the embodiment of
Various embodiments of an optical network can include more or less components than are shown in the embodiments of
Embodiments of an optical network can also utilize optical pathway sections of many different forms including single-mode fiber-optic cable, multi-mode fiber-optic cable, or plastic-optical cable, among other cable types. Embodiments can also utilize a signal router to provide similar functionality to that of a splitter.
However, in the illustration of
With respect to the transmission component 210, in some embodiments the component includes a transmitter 212 and a receiver 214. In some embodiments, transceivers are provided as both components 212 and 214. In such embodiments, a splitter and/or reflector may not be utilized, but rather, a signal is transmitted from transmitter/transceiver 212 and is received by receiver/transceiver 214. Although shown as an end point to the optical network 200, the receiver/transceiver 214 can be positioned in the middle of an optical pathway with a signal passing by or through the receiver/transceiver 214 and continuing through additional sections of optical fiber.
Also, in such embodiments, the logic circuitry 216 can communicate with the transmitter/transceiver 212 and/or the receiver/transceiver 214 to obtain temperature information. Temperature information can be obtained, for example, by accessing the temperature information at the components 212 and/or 214 (e.g., 112 and 114 in
In various embodiments, logic circuitry, such as circuitry 116 and 216 of
The outer connector portion 241 can have a variety of shapes and sizes, and can be formed from a variety of materials. For example, suitable materials include: elastomeric materials, including rubbers and polymers; and non-elastomeric materials, including polymers, ceramics, and metals. In some embodiments, a temperature sensitive material can be used as a portion or the entire outer connector portion 241. In such embodiments, the connector 240-1 or the temperature sensitive material of the outer connector portion 241 can be used as a heat sink or thermocooling component. In this way, heat can be removed from the components of an optical network.
Additionally, typically optical fiber is formed with a number of layers, such as an outer layer (e.g., a cladding or a coating) and an inner core (e.g., optical pathway), among others. In various embodiments, these layers can be provided, or emulated, with other materials to provide an optical pathway having dimensions and optical characteristics similar to that of the optical pathway sections. In such embodiments, the optical pathway of the connector 240-1 can be formed with temperature sensitive material and the other portions of the connector can be formed of materials that provide or emulate the characteristics of the materials of the optical fiber sections 221-0 and/or 221-1
In the embodiment described in the table of
In this, and various other manners described and/or inherently provided by optical networks and temperature sensing systems of the present disclosure, a number of temperatures can be measured within an optical network and at particular locations. The resulting information can indicate that a temperature source, such as source 270, is changing the temperature along the optical pathway. Such results can also indicate that the temperature of the optical network is within a particular range at a particular location.
If multiple connectors having the same characteristics are used, then it can be determined whether the temperature is consistently within this range or changes at a particular location. In some embodiments, this can be accomplished by inserting the particular connector at various locations along the optical pathway.
Based on this information, the type of materials used as connectors can be changed to avoid materials that absorb wavelengths within the detected temperature ranges and/or the wavelengths used can be changed to avoid wavelengths affected by the materials. In such embodiments, a tunable transmission component can be utilized to adjust one or more of the wavelengths utilized. In some embodiments, a tuner component can be used to adjust the transmission component. In such tunable embodiments, logic circuitry can be provided to analyze the temperature information and tune the transmission component accordingly.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same techniques can be substituted for the specific embodiments shown. This disclosure is intended to cover adaptations or variations of various embodiments of the invention. It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one.
Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of ordinary skill in the art upon reviewing the above description. The scope of the various embodiments of the invention includes various other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.
In the foregoing Detailed Description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may lie in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
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|U.S. Classification||385/4, 374/E01.018, 385/141, 374/E13.001, 374/E11.018, 385/144, 385/55, 385/5|
|Cooperative Classification||G01K2211/00, G02F2203/055, G01K1/14, G01K11/12, G02B6/3854, G01D5/35383, G01K2217/00, G01K13/00, G02F1/0147|
|European Classification||G01K11/12, G01K1/14, G01D5/353M, G01K13/00, G02B6/38D6M|
|Mar 14, 2006||AS||Assignment|
Owner name: LOCKHEED MARTIN CORPORATION, MARYLAND
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:STEVENS, RICK C.;HERNANDEZ, ALLISON;REEL/FRAME:017337/0060;SIGNING DATES FROM 20060301 TO 20060303
|Jul 9, 2012||REMI||Maintenance fee reminder mailed|
|Nov 25, 2012||LAPS||Lapse for failure to pay maintenance fees|
|Jan 15, 2013||FP||Expired due to failure to pay maintenance fee|
Effective date: 20121125